Use a cloth or gloves, as the battery will get very warm. Grab the ends of the battery with your gloves or cloth and try to pick up some metal objects.

Now the iron nail has become a magnet. This is really awesome.

Because the electricity flowing through the copper wire it passes through the iron nail. This makes it magnetic, Electromagnetic! When I remove the battery it is not magnetic anymore, this is because electricity is not flowing through the copper wire without the battery.